The present invention is related generally to the field of orthodontics, and more particularly to systems and methods for positioning teeth.
One objective in orthodontics is to move a patient's teeth to positions where the teeth function optimally and aesthetically. Conventionally, appliances such as braces are applied to the teeth of the patient by an orthodontist. Each appliance exerts continual forces on the teeth and gradually urges the teeth toward their ideal positions. Over a period of time, a treating professional such as an orthodontist adjusts the appliances to move the teeth toward their final destination.
Generally, the orthodontist specifies in a prescription the final tooth arrangement. The prescription is based on the orthodontist's knowledge and experience in selecting the intended final position of each tooth. The orthodontist or an assistant applies the treatment to move the teeth to their intended destination over a number of office visits. The process of attaching the braces to teeth is tedious and painful to the patient. Additionally, each visit reduces the “chair-time” available to the orthodontist that can be made available to another patient.
U.S. Pat. No. 5,975,893 entitled “Method and system for incrementally moving teeth,” issued to Chishti, et al. on Nov. 2, 1999, and assigned to the assignee of the present invention, discloses a system for repositioning teeth with a plurality of individual appliances. The appliances are configured to be placed successively on the patient's teeth and to incrementally reposition the teeth from an initial tooth arrangement, through a plurality of intermediate tooth arrangements, and to a final tooth arrangement. The system of appliances is usually configured at the outset of treatment so that the patient may progress through treatment without the need to have the treating professional perform each successive step in the procedure.
Additionally, U.S. application Ser. No. 09/313,291, filed May 13, 1999, entitled “System and Method for Determining Final Position of Teeth,” and assigned to the assignee of the present invention, discloses an apparatus and method to define a fit for a set of upper and lower teeth in a masticatory system of a patient by generating a computer representation of the masticatory system of the patient; and determining an occlusion from the computer representation of the masticatory system using one or more keys. U.S. application Ser. No. 09/556,022, filed Apr. 20, 2000, assigned to the assignee of the present invention, and entitled “System and Method for Determining Final Position of Teeth,” shows a system, apparatus and computer-implemented method for arranging a computer model of teeth. According to one implementation, the method includes generating an archform representing an arrangement of teeth; placing a plurality of teeth according to the archform; determining a differential distance between each tooth and its neighbors; and moving each tooth according to the differential distance.